A path-integral representation of central spin system immersed in an antiferromagnetic environment was investigated. To carry out this study, we made use of the discrete-time propagator method associated with a basic ...A path-integral representation of central spin system immersed in an antiferromagnetic environment was investigated. To carry out this study, we made use of the discrete-time propagator method associated with a basic set involving coherent states of Grassmann variables which made it possible to obtain the analytical propagator which is the centerpiece of the study. In this study, we considered that the environment was in the low-temperature and low-excitation limit and was split into 2 subnets that do not interact with each other. The evaluation of our system was made by considering the first neighbor approximation. From the formalism of the path integrals, it is easy to evaluate the partition function and thermodynamic properties followed from an appropriate tracing over Grassmann variables in the imaginary time domain. We show that the energy of the system depends on the number of sites <em>n</em> when <em>β </em><em></em><span></span>→ 0.展开更多
Aging is a dynamic and progressive process that begins at conception and continues until death.This process leads to a decrease in homeostasis and morphological,biochemical and psychological changes,increasing the ind...Aging is a dynamic and progressive process that begins at conception and continues until death.This process leads to a decrease in homeostasis and morphological,biochemical and psychological changes,increasing the individual’s vulnerability to various diseases.The growth in the number of aging populations has increased the prevalence of chronic degenerative diseases,impairment of the central nervous system and dementias,such as Alzheimer’s disease,whose main risk factor is age,leading to an increase of the number of individuals who need daily support for life activities.Some theories about aging suggest it is caused by an increase of cellular senescence and reactive oxygen species,which leads to inflammation,oxidation,cell membrane damage and consequently neuronal death.Also,mitochondrial mutations,which are generated throughout the aging process,can lead to changes in energy production,deficiencies in electron transport and apoptosis induction that can result in decreased function.Additionally,increasing cellular senescence and the release of proinflammatory cytokines can cause irreversible damage to neuronal cells.Recent reports point to the importance of changing lifestyle by increasing physical exercise,improving nutrition and environmental enrichment to activate neuroprotective defense mechanisms.Therefore,this review aims to address the latest information about the different mechanisms related to neuroplasticity and neuronal death and to provide strategies that can improve neuroprotection and decrease the neurodegeneration caused by aging and environmental stressors.展开更多
Currently, no specific treatment exists to promote recovery from cognitive impairment after a stroke. Dysfunction of the actin cytoskeleton correlates well with poststroke cognitive declines, and its reorganization re...Currently, no specific treatment exists to promote recovery from cognitive impairment after a stroke. Dysfunction of the actin cytoskeleton correlates well with poststroke cognitive declines, and its reorganization requires proper regulation of Rho-associated kinase(ROCK) proteins. Fasudil downregulates ROCK activation and protects neurons against cytoskeleton collapse in the acute phase after stroke. An enriched environment can reduce poststroke cognitive impairment. However, the efficacy of environmental enrichment combined with fasudil treatment remains poorly understood. A photothrombotic stroke model was established in 6-week-old male C57 BL/6 mice. Twenty-four hours after modeling, these animals were intraperitoneally administered fasudil(10 mg/kg) once daily for 14 successive days and/or provided with environmental enrichment for 21 successive days. After exposure to environmental enrichment combined with fasudil treatment, the number of neurons in the hippocampal CA1 region increased significantly, the expression and proportion of p-cofilin in the hippocampus decreased, and the distribution of F-actin in the hippocampal CA1 region increased significantly. Furthermore, the performance of mouse stroke models in the tail suspension test and step-through passive avoidance test improved significantly. These findings suggest that environmental enrichment combined with fasudil treatment can ameliorate memory dysfunction through inhibition of the hippocampal ROCK/cofilin pathway, alteration of the dynamic distribution of F-actin, and inhibition of neuronal death in the hippocampal CA1 region. The efficacy of environmental enrichment combined with fasudil treatment was superior to that of fasudil treatment alone. This study was approved by the Animal Ethics Committee of Fudan University of China(approval No. 2019-Huashan Hospital JS-139) on February 20, 2019.展开更多
Background:Evidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model.We determined which correlates best predict sensor-based physical activity(PA),sed...Background:Evidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model.We determined which correlates best predict sensor-based physical activity(PA),sedentary time(ST),and self-reported cell phone screen time(CST)in a large sample of youth,while considering a multiplicity of correlates.Methods:Using sensor-based accelerometry,we assessed the PA and ST of 2179 youths.A χ^2 automatic interaction detection algorithm was used to hierarchize the correlates associated with too much ST(>50th percentile),insufficient moderate-to-vigorous PA(MVPA)(<60 min/day),and prolonged CST(≥2 h/day).Results:Among youth 1014 years old,the correlates for being inactive consisted of being a girl,not having sport facilities in the neighborhood,and not perceiving the neighborhood as a safe place,whereas in the youth 1518 years old,the correlate for being inactive was not performing sports(9.7%chance of being active).The correlates for predicting high ST in the younger group was not performing sports(55.8%chance for high ST),and in the older group,the correlates were not owning a pet,perceiving the neighborhood as safe,and having inactive parents(63.7%chance for high ST).In the younger group,the greatest chances of having high CST were among those who were in the last elementary school years,who were girls,and who did not have friends in the neighborhood(73.1%chance for high CST),whereas in the older group,the greatest chance for having high CST was among those who were girls and had a TV in the bedroom(74.3%chance for high CST).Conclusion:To counteract ST and boost MVPA among youths,a specific focus on girls,the promotion of sport participation and facilities,neighborhood safety,and involvement of family must be prioritized.展开更多
为了形象客观地了解国内外2016—2020年环境土壤学相关研究的发展特点,本文收集了发表在Web of Science和中国知网上土壤环境领域的相关文章,利用Web of Science自带分析工具和文献计量学软件CiteSpace,分析了该领域的研究现状、发展方...为了形象客观地了解国内外2016—2020年环境土壤学相关研究的发展特点,本文收集了发表在Web of Science和中国知网上土壤环境领域的相关文章,利用Web of Science自带分析工具和文献计量学软件CiteSpace,分析了该领域的研究现状、发展方向和热点。结果显示,2016—2020年间土壤环境领域研究成果丰硕,发展平稳,中美两国发文占比超过国际领域发文的50%。国际环境科学类刊物Science of the Total Environment、Environmental Science and Pollution Research和Chemosphere发文量最高,土壤科学类期刊Geoderma、Catena、Plant and Soil和Soil Biology Biochemistry也在发文前十行列。从国际上看,土壤环境领域共有微生物群落、有机碳、生物炭改良、N2O排放、重金属、土壤侵蚀、机器学习、保护性农业8个重要研究方向及相关热点;国内研究紧跟国际发展,侧重于土壤有机质、养分和微生物等研究热点,也围绕土壤水分、生物炭、土壤侵蚀和作物产量等热点开展了大量研究。展开更多
In recent years,the monitoring systems play significant roles in our life.So,in this paper,we propose an automatic weather monitoring system that allows having dynamic and real-time climate data of a given area.The pr...In recent years,the monitoring systems play significant roles in our life.So,in this paper,we propose an automatic weather monitoring system that allows having dynamic and real-time climate data of a given area.The proposed system is based on the internet of things technology and embedded system.The system also includes electronic devices,sensors,and wireless technology.The main objective of this system is sensing the climate parameters,such as temperature,humidity,and existence of some gases,based on the sensors.The captured values can then be sent to remote applications or databases.Afterwards,the stored data can be visualized in graphics and tables form.展开更多
At present,many students finish high school and enroll the university education.University learning is very important education part in students'life,they are thinking about themselves,improve their identity and v...At present,many students finish high school and enroll the university education.University learning is very important education part in students'life,they are thinking about themselves,improve their identity and values,change their aims,produce knowledge and take skills into the future life and working.University offer different courses to learn,they interest in Arts,Commence and Science and satisfy all students'needs.There is an increasing number of Chinese students choose to study in New Zealand because they believe it is a safe place,it is cheaper than the other countries,and because New Zealand is an English speaking country.Most of the New Zealand universities offer foundation courses which give international students the opportunity to bring their English language skills and academic performance up to university entrance standard.This study is to find out Chinese and New Zealand higher education with some different aspects from curriculum,learning environment and evaluation.展开更多
文摘A path-integral representation of central spin system immersed in an antiferromagnetic environment was investigated. To carry out this study, we made use of the discrete-time propagator method associated with a basic set involving coherent states of Grassmann variables which made it possible to obtain the analytical propagator which is the centerpiece of the study. In this study, we considered that the environment was in the low-temperature and low-excitation limit and was split into 2 subnets that do not interact with each other. The evaluation of our system was made by considering the first neighbor approximation. From the formalism of the path integrals, it is easy to evaluate the partition function and thermodynamic properties followed from an appropriate tracing over Grassmann variables in the imaginary time domain. We show that the energy of the system depends on the number of sites <em>n</em> when <em>β </em><em></em><span></span>→ 0.
基金MT received studentship from Sao Paulo Research Foundation(2017/21655-6)HSB was a Brazilian National Council for Scientific and Technological Development researcher(425838/2016-1,307252/2017-5)This work was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil(CAPES)–Finance Code 001 and FAPESP(2016/07115-6).
文摘Aging is a dynamic and progressive process that begins at conception and continues until death.This process leads to a decrease in homeostasis and morphological,biochemical and psychological changes,increasing the individual’s vulnerability to various diseases.The growth in the number of aging populations has increased the prevalence of chronic degenerative diseases,impairment of the central nervous system and dementias,such as Alzheimer’s disease,whose main risk factor is age,leading to an increase of the number of individuals who need daily support for life activities.Some theories about aging suggest it is caused by an increase of cellular senescence and reactive oxygen species,which leads to inflammation,oxidation,cell membrane damage and consequently neuronal death.Also,mitochondrial mutations,which are generated throughout the aging process,can lead to changes in energy production,deficiencies in electron transport and apoptosis induction that can result in decreased function.Additionally,increasing cellular senescence and the release of proinflammatory cytokines can cause irreversible damage to neuronal cells.Recent reports point to the importance of changing lifestyle by increasing physical exercise,improving nutrition and environmental enrichment to activate neuroprotective defense mechanisms.Therefore,this review aims to address the latest information about the different mechanisms related to neuroplasticity and neuronal death and to provide strategies that can improve neuroprotection and decrease the neurodegeneration caused by aging and environmental stressors.
基金financially supported by the National Natural Science Foundation of China,Nos. 81672242,81972141 (both to YW)Shanghai Municipal Key Clinical Specialty of China,No. shslczdzk02702 (to YW)Shanghai Special Support Plan for High-Level Talents,Yang Fan Funds of China,No. 20YF1403500 (to QZ)。
文摘Currently, no specific treatment exists to promote recovery from cognitive impairment after a stroke. Dysfunction of the actin cytoskeleton correlates well with poststroke cognitive declines, and its reorganization requires proper regulation of Rho-associated kinase(ROCK) proteins. Fasudil downregulates ROCK activation and protects neurons against cytoskeleton collapse in the acute phase after stroke. An enriched environment can reduce poststroke cognitive impairment. However, the efficacy of environmental enrichment combined with fasudil treatment remains poorly understood. A photothrombotic stroke model was established in 6-week-old male C57 BL/6 mice. Twenty-four hours after modeling, these animals were intraperitoneally administered fasudil(10 mg/kg) once daily for 14 successive days and/or provided with environmental enrichment for 21 successive days. After exposure to environmental enrichment combined with fasudil treatment, the number of neurons in the hippocampal CA1 region increased significantly, the expression and proportion of p-cofilin in the hippocampus decreased, and the distribution of F-actin in the hippocampal CA1 region increased significantly. Furthermore, the performance of mouse stroke models in the tail suspension test and step-through passive avoidance test improved significantly. These findings suggest that environmental enrichment combined with fasudil treatment can ameliorate memory dysfunction through inhibition of the hippocampal ROCK/cofilin pathway, alteration of the dynamic distribution of F-actin, and inhibition of neuronal death in the hippocampal CA1 region. The efficacy of environmental enrichment combined with fasudil treatment was superior to that of fasudil treatment alone. This study was approved by the Animal Ethics Committee of Fudan University of China(approval No. 2019-Huashan Hospital JS-139) on February 20, 2019.
基金the Interdisciplinary Center of the Study of Human Performance(CIPER),I&D 472(UID/DTP/00447/2019)Faculty of Human Kinetics of the University of Lisbon,and supported by the Portuguese Foundation for Science and Technology,the Portuguese Ministry of Science.PBJ is supported by the Portuguese Foundation for Science and Technology(SFRH/BPD/115977/2016)DHN is supported by a grant from Comité Olímpico de Portugal(doctoral scholarshipCOP).
文摘Background:Evidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model.We determined which correlates best predict sensor-based physical activity(PA),sedentary time(ST),and self-reported cell phone screen time(CST)in a large sample of youth,while considering a multiplicity of correlates.Methods:Using sensor-based accelerometry,we assessed the PA and ST of 2179 youths.A χ^2 automatic interaction detection algorithm was used to hierarchize the correlates associated with too much ST(>50th percentile),insufficient moderate-to-vigorous PA(MVPA)(<60 min/day),and prolonged CST(≥2 h/day).Results:Among youth 1014 years old,the correlates for being inactive consisted of being a girl,not having sport facilities in the neighborhood,and not perceiving the neighborhood as a safe place,whereas in the youth 1518 years old,the correlate for being inactive was not performing sports(9.7%chance of being active).The correlates for predicting high ST in the younger group was not performing sports(55.8%chance for high ST),and in the older group,the correlates were not owning a pet,perceiving the neighborhood as safe,and having inactive parents(63.7%chance for high ST).In the younger group,the greatest chances of having high CST were among those who were in the last elementary school years,who were girls,and who did not have friends in the neighborhood(73.1%chance for high CST),whereas in the older group,the greatest chance for having high CST was among those who were girls and had a TV in the bedroom(74.3%chance for high CST).Conclusion:To counteract ST and boost MVPA among youths,a specific focus on girls,the promotion of sport participation and facilities,neighborhood safety,and involvement of family must be prioritized.
文摘为了形象客观地了解国内外2016—2020年环境土壤学相关研究的发展特点,本文收集了发表在Web of Science和中国知网上土壤环境领域的相关文章,利用Web of Science自带分析工具和文献计量学软件CiteSpace,分析了该领域的研究现状、发展方向和热点。结果显示,2016—2020年间土壤环境领域研究成果丰硕,发展平稳,中美两国发文占比超过国际领域发文的50%。国际环境科学类刊物Science of the Total Environment、Environmental Science and Pollution Research和Chemosphere发文量最高,土壤科学类期刊Geoderma、Catena、Plant and Soil和Soil Biology Biochemistry也在发文前十行列。从国际上看,土壤环境领域共有微生物群落、有机碳、生物炭改良、N2O排放、重金属、土壤侵蚀、机器学习、保护性农业8个重要研究方向及相关热点;国内研究紧跟国际发展,侧重于土壤有机质、养分和微生物等研究热点,也围绕土壤水分、生物炭、土壤侵蚀和作物产量等热点开展了大量研究。
文摘In recent years,the monitoring systems play significant roles in our life.So,in this paper,we propose an automatic weather monitoring system that allows having dynamic and real-time climate data of a given area.The proposed system is based on the internet of things technology and embedded system.The system also includes electronic devices,sensors,and wireless technology.The main objective of this system is sensing the climate parameters,such as temperature,humidity,and existence of some gases,based on the sensors.The captured values can then be sent to remote applications or databases.Afterwards,the stored data can be visualized in graphics and tables form.
文摘At present,many students finish high school and enroll the university education.University learning is very important education part in students'life,they are thinking about themselves,improve their identity and values,change their aims,produce knowledge and take skills into the future life and working.University offer different courses to learn,they interest in Arts,Commence and Science and satisfy all students'needs.There is an increasing number of Chinese students choose to study in New Zealand because they believe it is a safe place,it is cheaper than the other countries,and because New Zealand is an English speaking country.Most of the New Zealand universities offer foundation courses which give international students the opportunity to bring their English language skills and academic performance up to university entrance standard.This study is to find out Chinese and New Zealand higher education with some different aspects from curriculum,learning environment and evaluation.